Handle and latching mechanism for circuit breakers



Nov. 1, 1960 W. W. CAMP HANDLE AND LATCHING MECHANISM FOR CIRCUIT BREAKERS Filed April 8, 1958 2 Sheets-Sheet 1 --l| ll 3 ..;l INVENTOR.

WW/[WW CAMP Nov. 1, 1960 w. w. CAMP 2,958,751

HANDLE AND LATCHING MECHANISM FOR CIRCUIT BREAKERS Filed April 8, 1958 2 Sheets-Sheet 2 INVENTOR.

WIL LIAM WCAMP United States Patent HANDLE AND LA'ICHIN G MECHANISM FOR CIRCUIT BREAKERS William W. Camp, Lancaster, Pa., assignor to Heinemann Electric Company, Trenton, N .J., a corporation of New Jersey Filed Apr. 8, 1958, Ser. No. 727,213

6 Claims. (Cl. 200- 153) This invention relates to an improved handle and latching mechanism for circuit breakers which includes a transfer link for converting linear motion to circular motion in order to open and close a circuit breaker, and, more particularly, an electric circuit breaker of the type illustrated in Patent No. 2,360,922.

As illustrated in the aforementioned patent, it is usual to provide in circuit breakers of this type an external handle pivoted on the casing and capable of activating the collapsible linkage of the circuit breaker by means of the circular motion of the handle.

The object of this invention is to provide a push-pull driving member for the manual opening and closing of the contacts in the circuit breaker. Such object is accomplished by pivoting to the end of the reciprocal push-pull member a slotted link which is engaged by a pivoted triangular arm which is in turn linked with the tripping mechanism and the movable contact arm of the circuit breaker.

The principles and characteristic features of my invention and the best mode in which I have contemplated applying such principle will further appear from the following description and the accompanying drawings and illustration thereof.

In the drawings,

Fig. 1 is a side elevational view of my improved circuit breaker in non-operative position with the interior parts partly exposed;

Fig. 2 is a front elevational view of my improved circuit breaker;

Fig. 3 is an enlarged, cross-sectional, side elevational view of my improved circuit breaker showing the latching mechanism in inoperative or open position;

Fig. 4 is a fragmentary, top elevational view taken along the line 4-4 of Fig. 3;

Fig. 5 is a detached view of a portion of Fig. 3 illustrating the position of the latching mechanism when the circuit breaker is in the open position, that portion indicated by dotted lines illustrating the initial movement of the slotted transfer link as the reciprocating handle is pushed in slightly;

Fig. 6 is a view somewhat similar to Fig. 5 in which the reciprocating handle has been advanced so that the contact is closed but the handle is not in looked position, the locked position of the slotted transfer link being shown by dotted lines;

Fig. 7 is an enlarged, fragmentary view of the latching and tripping mechanism, the linkage as shown is ready to collapse because of the rotation of the catch;

Fig. 8 is an upright sectional view of the circuit breaker in operating position taken along the line 8-8 of Fig. 9; and

Fig. 9 is a fragmentary, side elevational view of the circuit breaker in closed position.

In the embodiment of my invention illustrated in the drawings the housing 1 of a circuit breaker 2 includes a cylinder-like extension member 3 projecting from the front of the housing in which a reciprocal handle or driving member 4 is free to move linearly. Force ap plied to the handle or driving member 4 moves the movable contact 5 into engagement with the fixed contact 6 thereby permitting current flow from one external terminal 23 to the other external terminal 2'4 by way of the contacts 5 and 6 and the overload coil 27 in series therewith.

To effect the movement above described a slotted, L-shaped transfer link 7 is connected to the end 8 of the handle 4 by a pintle 9. An elongated aperture 10 in the other end of the link 7 permits the link to move and pivot about the stud 11. The slot 12 in the corner of the link 7 is engaged by a pin 13 extending from one corner of the triangular link 14, which triangular link 14 pivots about the stud 15 located at a second corner of the link. The third corner of the triangular link 14 is pivotally connected with an end of a catch link 16 by the pintle 17 passing through apertures in the respective members. The opposite end of the catch link 16 is pivotally connected to one end of the link 18 by means of the pintle 19 and the other end of the link 18 is pivoted to contact carrying arm 20 by means of the pin 21 extending through apertures in such arm and link.

The arm 20 has an elongated aperture 22 near the lower end of such arm which permits the arm 20 to move and pivot about the stud 25 as it is forced into position by means of the handle 4 or forced out of contact position by the spring 26 which biases the upper end of the arm 20 carrying the contact 5 away from the fixed contact 6.

When force is applied to the handle 4 it moves toward the fixed contact 6 and in so doing moves the transfer link 7 about the stud 11 to the position shown in dotdash lines in Fig. 5. Such movement of the transfer link 7 in turn causes the trangular link 14 to pivot counterclockwise about the stud 15 so as to assume the position indicated in Fig. 6. When the triangular link 14 pivots about the stud 15 it causes the link members 16 and 18 to move the arm 20 about its pivot 25. In so doing the face of the contact 5 is moved into engagement with the face of the contact 6. It is to be understood that catch link 16 is kept from rotation about the pintle 19 by reason of the tooth 37 on the lower portion of such link engaging the convex portion of the pintle 35. Such engagement permits the operator to push the 'handle 4 and force the contact carrying arm 20 toward the fixed contact face 6 against the bias of the spring 26 carried on the stud 25 which seats in the frame 38. Rotation of the pintle 35, by means hereinafter explained, to the position shown in Fig. 7 permits the linkage mechanism to collapse and the contacts to be opened.

The position of the mechanism shown in solid lines in Fig. 6 is that obtained immediately prior to the locking of the handle 4 in locked position. If the handle 4 is released at this position the spring 26 promptly forces the arm 20 and the contact 5 away from the fixed contact 6 and back into position shown in Fig. 5. It is, therefore, necessary to push the handle 4 until the transfer link assumes the position indicated in Fig. 9. In such position pressure is on the stud 11, the pintle 9 having moved to the opposite side of a vertical line from such stud 11 as compared to the position of the pintle 9 before movement of the handle 4 to close the circuit breaker contacts. In the position shown in Fig. 9, the contacts 5 and 6 are locked together and cannot be moved except by the tripping of the armature or by pulling on the handle 4. A rim 39 may be provided on the end of the handle 4 to permit the ready grasping of the handle 4 for pushing or pulling.

The circuit breaker is automatically opened by an overload current passing through the coil 27 and attracting the armature 28 thereby causing the linkage mechanism to collapse. The armature 28 forms one leg of an L-shaped lever the other leg 29 of which has a projection 39 which, when the armature 28 pivots about the stud 31 as itis drawn toward-the pole piece 32 and coil 27 on overload, moves toward and engages the member 33 extending from the, locking member 34. The locking member 34 is pivotally connected to the link 18 by the pintle 35 which has a flat face 36. Such flat face 36 is sufficiently recessed to permit the passage of the tooth 37, located on the lower portion of the catch link 16, past the pintle 35-when the face 36 is brought into line with the tooth by rocking the member 34 and pintle 35 clockwise by means of the leg 29,'Fig. 7. When the flat face 36 is in line with the end of the tooth 37 the pintle will slide past the tooth 3'7 under pressure from the spring 26 transmitted through the arm 20 and link 18. The movement of the face 36 past the tooth 37 permits the separation of the contact from the contact 6 and the collapse of the linkage mechanism. Thereupon the linkage will assume the position shown in Figs. 3 and 5 and the handle 4 will be ready for resetting or closing of the contacts. It will not, of course, be possible to hold the contacts closed on overload, except momentarily, by holding the handle in as the catch link 16 will always permit the movement of thecontaot arm to rotate clockwise about the stud 25 as long as the end 36 keeps the locking member 34 and the pintle 35 turned so that the tooth 37 cannot keep engagement with the convex portion 4t) of the pintle 35.

Having described my invention, I claim:

1. A latching mechanism for electric circuit breakers to engage and disengage a movable contact member to a fixed contact member comprising a linearly reciprocable handle, a slotted transfer link connected to one end of said handle, a pivoted trangular rigid arm having a pin projecting through one corner thereof and into the slot in said transfer link, and means including a catch link for joining another corner of said triangular arm to the movable contact member, said last mentioned means including a latch for restraining movement of said catch link.

2. A latching mechanism for converting linear motion to circular motion in order to shift a movable contact in a circuit breaker comprising a linearly reciprocable handle, a triangular rigid link pivotable on a fixed stud and connected to said movable contact, and a pivotable L- shaped transfer link having a slot, said pivotable L-shaped transfer link being pivotally connected by one l'egto said handle and engaged with said triangular link by means of a member projecting from said triangular arm and movable in said slot.

3. A latching mechanism for converting linear motion to circular motion in a circuit breaker in order to move a movable contact into engagement with a fixed contact comprising a driving member having a pintle at one end thereof which engages one end of a slotted transfer link pivoted on a stud, a pivoted triangular rigid link having a first corner for pivoting the triangular link about a fixed stud, said triangular link having a second corner thereof joined to said trans-fer link by means of a pin extending from said corner into said slot, means connecting a third corner of said triangular link to links joined to the said movable contact thereby permitting the movement of said contact by the application of force applied to the driving member.

4. A latching mechanism for electric circuit breakers whereby linear motion is converted to circular motion to close a pair of contacts in said circuit breaker comprising a fixed contact and a movable contact, a driving member through which operating force is applied, and means for transmitting said driving force from said driving member to said movable contact, said means including a slotted transfer link pivotally connected to one end of the drivingmember, a catch link, and a rigid triangular link having a first portion pivotally connected to said transfer link and a second portion pivotally connected to said catch link, said triangular link being pivotable about a fixed stud disposed intermediate the pivotal connections of said triangular link to said transfer link and to said catch link, and said catch link and said second portion of said triangular link being substantially straight when the contacts are closed and being substantially bent when the contacts are open.

5. A latching mechanism for closing and opening a circuit breaker comprising a linearly operated driving member, a slotted transfer link ivotally connected to said driving member, a pivotable rigid triangularlink having afirst corner portion joined to said transfer link by apin extending into the slot, a catch link, said triangular linkhaving a second cornerportion pivotally connected to said catch link, a movable contact member, a pivotal link connected to said contact member and to said catch link, said triangular link having a third corner portion pivotable about a fixed stud; and said pivotal link, said catch link,- and said second corner portion being substantially straight when the circuit breaker is closed.

6. A latching mechanism for electric circuit breakers whereby linear motion is converted to circular motion to close a pair of contacts in said circuit breaker comprising a fixed contact and a movable contact arm, said movable contact arrn being biased to the contacts open position, a. driving member through which operating force is applied, and means for transmitting said driving force from said driving member to said movable contact arm, said means includinga slotted transfer link pivotally connected to one end of the, driving member, connect ing members including a catch link and a pivotal'link pivotally connected to each other, a latch structure co,- operating with said catch link tending to maintain said pivotal linkand said catch, link in force transmittingrelationship, and a rigid triangular link having -a first portion pivotally connected to said transfer link by a pin extending into the slot, one of said connecting members being pivotally connected to a second portion of said triangular link and the other pivotally to said movable contact arm, said triangular link being pivotable about a fixed stud, said transfer link being rotatable about a fixed stud; said triangular link and said transfer link being simultaneously rotatable by said driving member until suflicient pressure is placed upon the fixed stud of said transfer link to resist the tendency of the contacts to open due to the bias on the movable contact arm.

References Cited in the file of this patent UNITED STATES PATENTS 2,134,593 Wulsten o r. 25, 193s 2,689,896 Kuhn et al. p Nov. 28, 1951 2,811,606 Norden Oct. 29, 1957 FOREIGN PATENTS 480,910 Germany 'Aug. 10, 1929 568,429 Great Britain Apr. 4, 1945 1,140,336 France h Feb. 25, 1957 

